Automatic valve mechanism



Oct. 23, 1945. c. M. TERRY AUTOMATIC VALVE MECHANISM Filed June 17, 1943CHARLES M TERRY Patented Oct. 23, 1945 AUTOMATIC VALVE MECHANISM CharlesM. Terry, Decatur, Ill., assignor to A. W. Cash Company, Decatur, 111.,a corporation of Delaware Application June 17, 1943, Serial No. 491,100

8 Claims.

This invention relates to automatic valve mechanisms, and moreparticularly to the construction and arrangement of a valve which willoperate to maintain a substantially constant drop in the pressure of thefluid traveling therethrough.

In certain installations of oil cooling equipment there is need for anautomatic valve for use in a by-pass line. The viscosity of oil variesgreatly with its temperature, and if an oil cooler is designed for anormal pressure drop of say eleven pounds, it will be found that whenstarting up with the oil cold the pressure drop may run as high as fortyor fifty pounds. This high pressure drop may be avoided by allowing aconsiderable portion of the oil to by-pass the cooler through a suitablevalve, which should preferably open automatically to the requiredextent.

It is accordingly one object of the invention to provide an automaticvalve mechanism of simple, inexpensive and dependable construction whichwill restrict the flow of fluid in such a manner as to maintain asubstantially constant drop in the fluid pressure. v

It is a further object of the invention to provide an automatic valvemechanism arranged to respond to variations in a fluid pressurediilerential and so constructed as to operate steadily without surgingor fluttering.

It is a further object of the invention to provide an automatic valvemechanism arranged to respond to changes in the pressure drop across thevalve and so constructed that a slight increase in the said pressuredrop will cause the valve to open to a comparatively large extent.

It is a further object of the invention to provide an automatic valvemechanism arranged to maintain a substantially constant drop in thefluid pressure and capable of handling fluid at a rate of flow which isvery high in proportion to the size of the mechanism.

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention Fig. 4 is a fragmentary sectional viewshowing a further modification.

The embodiment illustrated comprises a hollow body or casing I0,preferably of integral construction, which is divided internally by apartition II to provide an inlet chamber I2 and an outlet chamber I 4.The body I0 is provided on opposite sides with external openings l5 andit which communicate with the inlet and outlet chambers respectively,these openings being surrounded by flanges ll so that the body may bereadily connected to inlet and outlet pipes (not shown). The partition Il is shaped as a horizontally positioned U, with the interior of the Uforming a portion of the outlet chamber 14. Each of the two horizontalbranches: of the U is provided with a cylindrical port It, the two portsbeing vertically aligned and of the same diameter. Within these portsthere is mounted a vertically slidable valve member I! of the balancedtype having two cylindrical portions or disks 20 to control the flowthrough the ports, these disks being connected by a vertical stem 2 8.Guide wings 22 depend from each disk 20 to engage the walls of the portsand maintain the valve member in proper alignment with the ports. Upwardmovement of the valve member open the ports for increased flow of fluidtherethrough.

Means is provided to steady the movements-of this valve member andprevent surging or fluttering thereof. For this purpose the body in isshaped to provide a vertical cylindrical bore 24 directly beneath thelower port l8 and aligned therewith. A plate 25 is secured to the bottomof the body to close the lower end of this bore Within the bore 24 thereis mounted a vertically slidable piston 25 which is connected to" thelower disk 20 of the valve member by means of a verti cal stem 28. Arestricted port 29 extends through the piston 26 to form a by-pass. Thisconstrucsteadying effect is obtained.

In order to control the operation of the valve in accordance with thefluid pressure drop across the same, the body [0 is shaped to provide anopening in the form of a vertical cylindrical bore 3| directly above theupper port it and aligned therewith. This bore preferably hassubstantially the same diameter as the port. The upper end of the bore3| communicates with the interior of a chamber 32 which is secured tothe top of the body. A piston 33, forming a fluid-pressure re sponsivedevice, is vertically slidable in the bore 3!, and in the embodimentshown in Fig. 1 this piston is integral with the valve member IS. The

piste; 33 and valve member I! are urged downward! by means of a verticalcoiled compression spring 35 which extends upwardly into the chamher 3;.The upper end of the spring engages a button 38 on the lower end or avertical screw 31 which is threaded through the top of the chamber 3'2.A ca 33 is mounted on the upper portion of the s rew to engage the topof the spring chamber and prevent any leakage of fluid. The interior oithe spring chamber is connected with the outlet chamber l4, and for thispurpose a passage til extends downwardly through the center of the upperdisk 20 and the stem 2| to intersect with a passage 4| which extendsdiametrically through the sham 2'.

It will now be apparent that the valve member i3 is -irged upwardlytoward its open position by the p-essure of the fluid in the inletchamber i2, this pressure being eilective beneath the dashpot piston 26and the lower valve disk 20. This upward force is opposed by thedownward force of the spring 35 and by the fluid pressure inside thechamber 32, this pressure being effective above the pi. ton 33 and beingequal (under static conditions) to the pressure in the outlet chamber.Thus the valv will remain closed so long as the fluid pressuredifferential between the inlet chamher the outlet chamber is below apredetermined value which is dependent upon the adjustment of the screw31. Whenever the pressure differential exceeds the said predeterminedvalue, the valve member will be raised to allow flow through the portsl8.

Preferably the construction is such that a comparatively slight increasein the pressure differential will open the valve widely and thus allowlarge volume of fluid to flow through the valve. This is accomplished byutilizing the flow of the J cause a reduction in the pressure aboveiston 33 as compared with the pressure in outlet chamber I4. For thispurpose I prefer ze the fluid flowing through the upper port treate anaspirating effect on the passage indicated by the small arrows in Fig.1, id entering the outlet chamber l4 through per port l8 tends to travelat comparatively locity downwardly along the stem 2 E. Diabove thepassage 4| this stem is provided baflle plate in the form of anoutwardly ng flange or rib 43 which preferably comsurrounds the valvestem. This baffle direct the downwardly flowing fluid in an ,1 ddirection away from the stem, and this 3 effect of reducing the pressurebeneath stile and thereby aspirating fluid out of the in; er 32 throughthe passages 40 and 4!. -esult the pressure above the piston 33 is i,causing the valve to open much farther would otherwise, and permitting amuch flow to take place. The lower surface baiile 43 forms a downwardlyfacing s of the larger sizes are of course conte to larger pipes, andthese pipes are so d heavy that in some cases they may impreciablemechanical stresses on the valve and distort the same slightly. Thedash- ;on 26 will ordinarily be made a rather t in its bore 24, andhence will always l eely. The valve disks 20 and the upper 33 shouldhowever fit rather closely in their ive bores in order to minimizeleakage of id any appreciable distortion of the valve ght cause them tobind. In order to avoid sibility, the piston 33 in the larger valvesBEST AVAILABLE COPY may be made separate from the valve disks 20, asshown in Fig. 3. With this construction the piston merely rests on theupper valve disk and is free to move laterally thereon, so that slightmisalignment of the bores will not prevent free sliding of the valvemember and pistons.

In Fig, 4 there is shown a further modification showing a slightlydiflerent arrangement for obtainlng the desired aspirating eflect. Inthis embodiment the valve stem I9 is somewhat reduced in diameter toprovide a downwardly facing shoulder 46 beneath the upper valve disk 20and adjacent to the valve stem. The passage 40- of Fig. l is replaced inFig. 4 by one or more substantially vertical passages 41 which extendthrough the upper disk 20, with their lower ends opening through theshoulder 46. When the valve is open, the fluid traveling downwardlythrough the upper port l8 will create a zone of relatively low pressuredirectly beneath the shoulder 46, and fluid will therefore be aspiratedout of the chamber 32 through the passages 41. This will cause the valveto open much farther and permit th rate of flow to increaseconsiderably.

The operation of the invention will now be apparent from the abovedisclosure. The screw 31 will be adjusted so that the valve will startto open at a desired pressure differential of say fifteen pounds. Solong as the pressure differential is less than fifteen pounds, the fluidpressure above the piston 33 added to the force of the spring 35 willhold the valve closed against the fluid pressure beneath the lower valvedisk 20.

35 If however the pressure diflerential exceeds flfthrough the upperport will travel downwardly along the stern l9 until it encounters thebaflie 43, which will deflect the fluid outwardly away from the stem andthereby aspirate fluid from the passage 4| beneath the baflle.- Thiswill reduce the pressure above the piston 33 to a value appreciablybelow the pressure in the outlet chamber 84, and cause the valve to openmuch farther than it would otherwise. As a result flow can take place ata comparatively high rate with only a slight increase in the pressuredifferential. In order to ascertain the efiect of the baifle 43, testswere run on a valve mechanism 1% inch nominal pipe size both with andwithout the baille. In each case the valve was adjusted to start openingat a pressure difierential of 14 pounds per square inch. Without thebaffle an increase of 3 pounds in the pressure differential produced aflow of 22 gallons per minute, whereas with the baiiie the same increasein the pressure differential produced a flow of gallons per minute. Thusthe addition of the baille increased the capacity of the valve five-foldunder these particular conditions, with the pressure differential acrossthe valve l7 pounds. Without the bafiie it was found that the pressuredifferential had to be increased to 20 pounds to produce a flow of only42 gallons per minute. The practical advantages of this feature will beapparent to those skilled in the art. The mechanism operates smoothly atall times, the dashpot 26 serving to prevent surging and fluttering. Thebores 3|, i8 and 24 in the valve body are all aligned and of the samediameter. They can all be machined at one set up, greatly decreasing thecost of manuiacture. The entire mechanism is simple, inexpensive anddependable. The operation or the embodiment shown in Fig. 4 is similarto that of the Fig. 1 construction. The fluid flowing downwardly i'romthe upper port It will creates 'low pressure zone beneath the shoulderll similar to the low pressure zone beneath the baille n at Fig. 1. Thusfluid will be aspirated from the passages 41, and the pressure above thepiston I3 willbe reduced, causing the valve to open and allow anincreased flow oi fluid tor a given pressure diiierential.

Inthe claims, certain terms such as upper," "lower." vertical.""horizontal," and the like are employed. It should be noted however thatthe apparatus can be mounted in positions other than that illustrated,andsuch terms are not intended as limitations except as they describethe relative positions of the various parts.

.Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is: g

1. Automatic valve mechanism comprising a hollow-body, a partitionshaped as a horizontally positioned U dividing the interior of the bodya into an inlet chamber and an outlet chamber, the

interioroi the U forming a portion of the outlet chamber and each branchoi the U having a port therein withthe ports vertically aligned, a

vertically reciprocable-valve member having two with the space above thepiston, means to utilize the fluid flowing through the upper port toaspirate fluid from the passage and thereby reduce the pressure abovethe piston. and a sprin urging the valve member downwardly.

2. Automatic valve mechanism comprising a hollow body, a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber,

the interior of the U forming a portion of the outlet chamber and eachbranch of the U having a port therein with the ports vertically aligned,a vertically reciprocable valve member having two vertically spaceddisks thereon connected by a central stem, the disks being associatedwith the respective ports to control the flow therethrough andgclosingin a downward direction, the body 3 tically spaced disks thereonconnected by a central stem, the disks being associated with the report,a piston slidable in the bore and connected to the valve member, thevalve member having a e therein which extends through the stem, theupper end of the passage communicating with the space above the pistonand its lower end communicating with the outlet chamber, and means-toutilize the fluid flowing through the p r port to aspirate fluid fromthe lower end oi the passage and thereby reduce the pressure above thepiston, and a spring urging the valve member downwardly;

4. Automatic valve mechanism comprising a hollow body. a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber, the interior of the Uforming a portion of the outlet chamber and each branch 01' the U havinga port therein with the ports vertically aligned, a verticallyreciprocable valve member having two vertically spaced disks thereonconnected by a central stem, the disks being associated with therespective ports to control the flow therethrough and closing in adownward direction, the body having a vertical bore therein above theupper port, a piston slidable in the bore and connected to the valvemember, the valve member being shaped to provide a downwardly racingshoulder adjacent the stem and a passage connecting the -space directlybeneath the shoulder with the space above the piston, whereby fluidflowing downwardly from the upper port past the shoulder will aspiratefluid from the passage and reduce thepressure above the piston, and aspring urging the valve member downwardly.

3. Automatic valve mechanism comprising a hollow body, a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber, the interior of the Uforming a portion or the outlet chamber and each branch or the U havinga port therein with the ports vertically aligned, a verticallyreciprocable valve member having two verhaving a vertical bore thereinabove the upper port, a piston slidable in the bore and connected to thevalve member, the valve member having a passage therein which extendsthrough the stem, the upper end 01' the e communicating with the spaceabove the piston and its lower and opening laterally into the outletchamber, a baille on the stem arranged to direct'the fluid which flowsdownwardly along the stem from the upper port away from the lower endoi? the passage and thereby reduce the pressure above the piston, and aspring urging the valve member downwardly.

5. Automatic valve mechanism comprising a hollow body, a partitionshaped as a horizontally positioned U'dividing the interior of the bodyinto an inlet chamber and an outlet chamber, the interior of the Uforming a portionoti the outlet chamber and each branch of the U havinga port therein with the ports verticallyaligned, a verticallyreciprocable valve member having two vertically spaced disks thereonconnected by a central stem, the disks being associated. with therespective ports to control the flow therethrough and closing in adownward direction, the body having an opening th'erein above the upperport, a vertically movable fluid-pressure responsive device closing thesaid opening and connected to the valve member, the'valve member havinga passage therein which connects the outlet chamber with the space abovethe said device, means to utilize the fluid flowing through the upperport to aspirate fluid from the passage and thereby reduce the pressureabove the said device, and a spring urging the valve member downwardly.

6. Automatic valve mechanism comprising a hollow body. a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber, the interior or the Uforming a portion of the outlet chamber and each branch of the U havinga port therein with the ports vertically aligned, a verticallyreciprocable valve member having two vertically spaced disks thereonconnected by a central stem, the disks being associated with therespective ports to control the flow therethrough and closing in adownward whereby fluid flowing downwardly irom the lip-- per port pastthe shoulder will aspirate fluid from the passage and reduce thepressure above the said device, and a spring urging the valve memberdownwardly.

7. Automatic valve mechanism comprising a hollow body, a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber, the interior of the Uforming a portion of the outlet chamber and each branch of the U havinga port therein with the ports vertically aligned, a verticallyreciprocable valve member having two vertically spaced disks thereonconnected by a central stem, the disks being associated with therespective ports to control the flow therethrough and closing in adownward direction, the body having an opening therein above the upperport, a vertically movable fluid-pressure responsive device closing thesaid opening and connected to the valve member, the valve member havinga passage therein which extends through the stem, the upper end of thepassage communieating with the space above the said device and its lowerend communicating with the outlet ea set chamber, and means to utilizethe fluid flowing through the upper port to aspirate fluid from thelower. end of the passage and thereby reduce th'e pressure abovethe-said device, and a spring urging the valve member downwardly.

8. Automatic valve mechanism comprising a hollow body, a partitionshaped as a horizontally positioned U dividing the interior of the bodyinto an inlet chamber and an outlet chamber,

the interior of the U forming a portion oi the outlet chamber and eachbranch of the U having a port therein with the ports vertically aligned,a vertically reciprocable valve member having two vertically spaceddisks thereon connected by a central stem, the disks being associatedwith the respective ports to control the flow therethrough and closingin a downward direction, the body having an opening therein above theupper port, a vertically movable fluid-pressure responsive'deviceclosing the said opening and connected to the valve member, the valvemember having ,a-passage therein which extends through the stem, the

upper end of the passage communicating with the upper port away from thelower end or the passage and thereby reduce the pressure above the saiddevice, and a spring urging the valve member downwar ly.

Y CHARLES M. TERRY.

